Search PubMed⌕ Search

Biomedical subjects

J Hedley-Whyte

Publications and source records attributed to J Hedley-Whyte.

At least 19 recordsLinked to original sources
PubMed1999

Equipment standards: history, litigation, and advice.

The authors present a concise history of the development of national and international standards for surgical equipment. Standards-writing organizations, surgical and other specialty societies, universities, test houses, and the U.S. government have influenced this process, which is now manifested in complex interactions between national and international standards-writing organizations, and in CE (Conformité Europeene) marks being placed on surgical equipment in the United States and elsewhere. The history of litigation in standards development is also reviewed. Recommendations to maximize patient safety and to help ensure successful, cost-effective defense in litigation for surgeons who use equipment and may suffer its malfunctions are given. Overall, the complicated oversight of surgical equipment standards and the approval process appears to be contributing to the improving and outstanding results of U.S. surgery reported by the U.S. government.

Equipment Failure↗
PubMed1994

Contributions of the surgical sciences to a reduction of the mortality rate in the United States for the period 1968 to 1988.

OBJECTIVE: The authors sought to determine whether advances in the surgical sciences have led to a reduction in mortality rates for diseases treated by surgery during the past 25 years. They also wished to study changes in health care manpower for perioperative care during this period. SUMMARY BACKGROUND DATA: Surgical operations requiring general anesthesia in the United States have risen to 25 million per year at an annual cost of approximately $125 billion. During the period 1968 to 1988, the number of anesthesiologists per 100,000 persons in the United States increased 98%, although the number of surgeons remained relatively constant. Between 1980 and 1989, the number of radiologists per 100,000 persons decreased to 29% below the figure for 1965. Membership in specialized nursing societies increased dramatically. METHODS: The authors used vital statistics data from the National Center for Health Statistics (NCHS) to examine the mortality rates for diseases of the prostate, appendix, and gallbladder; hernia and intestinal obstruction; and ulcerative disease of the stomach and duodenum for the years 1968, 1978, and 1988. NCHS hospital discharge data were used to derive the rates of hospitalization and surgery for these conditions. Information on changes in health care manpower was obtained from published and other sources. RESULTS: The mortality rates for the five diseases studied decreased from 40% to 69% between 1968 and 1978. Between 1978 and 1988, the mortality rates caused by benign prostatic hyperplasia declined an additional 54% and by appendicitis, an additional 43%. Deaths attributable to the other conditions remained relatively constant. The rates of hospitalization and surgery for these conditions varied. CONCLUSIONS: Advances in surgery, anesthesiology, and information transfer and the availability of intensive care units and specialized hospital personnel have resulted in reduced mortality rates for diseases treated by surgery.

Appendicitis↗
PubMed1993

Laminectomy and the treatment of lower-back pain in Massachusetts.

During 1984-85, laminectomy rates in Massachusetts demonstrated a 2.2-fold variation among districts. Thirty-five percent of laminectomies occurred in 7 of the 108 hospitals studied. Approximately 81% of laminectomies were performed by neurosurgeons. Rates of laminectomy decline with increasing age after 65, while rates of hospitalization for lower-back pain rise.

Adolescent↗
PubMed1992

Lower back pain. Laminectomies, spinal fusions, demographics, and socioeconomics.

The models and analyses used in this study represent an important step in the continued search for the optimum use of surgery for the treatment of lower back pain. The likelihood of patients who are hospitalized with lower back pain in Massachusetts receiving either laminectomies or spinal fusions or both was increased when any of the following demographic, socioeconomic, or medical characteristics were present: white, male, well insured, young, routine admission, admitted to a medium-sized hospital, admitted to a teaching hospital, admitted to a hospital with a high occupancy rate, and discharged home.

Back Pain↗
PubMed1988

Concentration of Mycobacterium avium by hospital hot water systems.

Water from 34 sites on two temporarily vacant hospital floors was analyzed for the presence of mycobacteria. These sites included 18 cold water taps and 16 hot water taps, including shower heads. A total of 14 sites (41%) demonstrated the presence of Mycobacterium avium as confirmed by biochemical characterization, DNA/rRNA probe analysis, and seroagglutination. Of positive sites, 11 were hot water sources with an average temperature of 55 degrees C and yielding up to 500 colony-forming units per 100 mL. Seven of 11 strains analyzed for glycolipid antigens were identified with the type 4 serovar, the preponderant serovar of M avium in patients with acquired immunodeficiency syndrome from the Boston area. Potable hot water systems, particularly those that generate aerosols, may contain concentrations of M avium greater than those found in cold water systems and could serve as an environmental source for colonization and infection of immunocompromised persons.

Boston↗
PubMed1988

Effects of tracheal intubation on laryngeal acoustic waveforms.

To assess the feasibility of noninvasive detection of laryngeal injury after tracheal intubation through acoustic waveform measurements, we studied the effects of intubation on "time-expanded" acoustic waveforms of the larynx in 16 patients given general anesthesia, 9 with and 7 without tracheal intubation. Recordings of several utterances were obtained by means of a microphone and an accelerometer attached to the skin at the midpoint of the suprasternal notch. Recordings were taken the day before induction of general anesthesia, 20 minutes after extubation, and 2 and 4 days after extubation. Waveforms of the recordings were subsequently assessed visually for features different from those of normal phonation as determined in preliminary studies. Waveforms in several of the recordings taken soon after extubation showed marked intraperiod and interperiod irregularities. These abnormalities improved and disappeared over the following 4 days. No changes were observed in the acoustic waveforms of seven patients given general anesthesia without tracheal intubation. The analysis of time-expanded acoustic waveforms of the larynx indicates that this technique has considerable potential as a sensitive, noninvasive technique that helps to evaluate the effects of tracheal intubation on laryngeal function, a technique that warrants further study and evaluation.

Adult↗
PubMed1987

Bacterial colonization and endotoxin content of a new renal dialysis water system composed of acrylonitrile butadiene styrene.

We measured endotoxin and bacterial levels in tap water, in water purified by reverse osmosis, and in dialysate samples over a 4-month period in a new 10-bed renal dialysis unit. Water treated by reverse osmosis is conducted to the 10 stations through 111 m of piping composed of acrylonitrile butadiene styrene (ABS). All determinations were made prior to the opening of the unit and after the system was purged for 35 h with all bedside station taps open. Formaldehyde disinfection of the piping system was attempted with a recommended protocol after 11 weeks by feeding 2.5 liters of 37% formaldehyde (0.85%, vol/vol) into the delivery system. Prior to water purging, 24 ng of endotoxin per ml was detected. This level decreased to 2.0 ng of endotoxin after the purging. Levels of endotoxin remained below 1.0 ng of endotoxin per ml throughout the duration of the study. In contrast, the level of viable microorganisms recovered from the treated water was approximately 3.5 X 10(4) CFU/100 ml. Even after disinfection of the system, there was no significant decrease in culturable bacteria from the water even though endotoxin levels were lower. Species isolated from the renal dialysis system were predominately pseudomonads, whereas species isolated from the tap water were Bacillus and Flavobacterium species. ABS provides a surface suitable for long-term colonization and growth of bacteria. Currently recommended decontamination protocols are ineffective in removing potentially pathogenic bacteria from ABS pipes and thus constitute an increased risk to patients undergoing dialysis.

Acrylic Resins↗
PubMed1985

E. coli peritonitis and bacteremia cause increased blood-brain barrier permeability.

Impaired mental status is a poorly understood manifestation of sepsis and may be associated with altered permeability of the blood-brain barrier. To examine the possibility that sepsis affects permeability of the blood-brain barrier, rats were infected with a peritoneal implant consisting of sterilized feces, barium sulfate, and 10(8) colony forming units (CFU) of Escherichia coli. Using this model, reproducible episodes of peritonitis with bacteremia resulted. Rats were sacrificed hourly after 5 min circulation of 100 mg horseradish peroxidase. Animals were perfused-fixed and the brains removed. Representative coronal sections were stained for peroxidase reaction product and cerebral blood vessels were examined microscopically for evidence of HRP staining and extravasation. The number of stained cerebral vessels from infected rats was increased at all times compared to uninfected control rats. Extravasation of horseradish peroxide within neuropil was significantly higher in hours 1, 4 and 5 as compared to controls. The lack of significant increase in hours 2 and 3 may suggest transient closing or repair of the tight junctions. We conclude that peritonitis and bacteremia are associated with increased permeability of the blood-brain barrier.

Animals↗
PubMed1985

Detection of gram-negative bacteremia by limulus amebocyte lysate assay: evaluation in a rat model of peritonitis.

A spectrophotometric Limulus amebocyte lysate assay using lysis filtration and centrifugation has been developed for the detection of gram-negative bacteria in blood. The assay is directed at detection of endotoxin in viable and nonviable bacteria present in the blood-stream and not detection of free endotoxin in plasma. The assay was evaluated in a model of peritonitis in which rats were challenged with an inoculum consisting of sterilized human feces, barium sulfate, and one of eight species of bacteria. This assay was able to detect gram-negative bacteremia due to Escherichia coli, Pseudomonas aeruginosa, Serratia marcescens, Proteus mirabilis, and Klebsiella pneumoniae in the rat model when compared with sham-inoculated uninfected rats. The assay failed to detect bacteremia due to Bacteroides fragilis or Staphylococcus aureus, nor was there a significant rise in absorbance when a pellet containing sterilized feces was implanted in the rat.

Animals↗
PubMed1982

Aspiration of gastric bacteria in antacid-treated patients: a frequent cause of postoperative colonisation of the airway.

The gastric and upper-airway flora of 60 consecutive patients treated with antacids or cimetidine in a respiratory/surgical intensive-therapy unit were studied. In 52 (87.0%) patients one or more organisms were cultured simultaneously from both upper airway and stomach. A sequence of transmission was clear in 17 of these patients. Pneumonia due to gram-negative bacilli developed in 31 patients; in most cases the causative organisms were of gastric origin. No pneumonia developed in the 8 patients whose gastric and upper-airway flora were different. The number of gram-negative bacilli in gastric aspirates correlated with the pH of the gastric aspirate. Treatment of seriously ill patients with antacids or cimetidine may encourage airway colonisation and predispose the patients to pneumonia caused by gram-negative bacilli.

Antacids↗